Continuum Mechanics In The Earth Sciences

This interdisciplinary book provides graduate students in geophysics, planetary physics and geology with a class-tested, accessible overview of continuum mechanics.

The study of the Earth and the environment requires an understanding of the physical processes within and at the surface of the Earth. This book will allow the student to develop a broad working knowledge of mechanics and its application to the earth and environmental sciences. The mathematics are introduced at a level that assumes only an understanding of first-year calculus. The concepts are then developed to allow an understanding of the basic physics for a wide range of natural processes. These are illustrated by examples from many real situations, such as the application of the theory of flow through porous media to the study of groundwater, the viscosity of fluids to the flow of lava, and the theory of stress to the study of faults. The breadth of topics will allow students and professionals to gain an insight into the workings of many aspects of the Earth's systems.

Modern continuum mechanics is the topic of this book. After its introduction it will be applied to a few typical systems arising in the environmental sciences and in geophysics. In large lake/ocean dynamics peculiar effects of the rotation of the Earth will be analyzed in linear/nonlinear processes of a homogenous and inhomogenous water body. Strong thermomechanical coupling paired with nonlinear rheology affects the flow of large ice sheets (such as Antarctica and Greenland) and ice shelves. Its response to the climatic forcing in an environmental of greenhouse warming may significantly affect the life of future generations. The mechanical behavior of granular materials under quasistatic loadings requires non-classical mixture concepts and encounters generally complicated elastic-plastic-type constitutive behavior. Creeping flow of soils, consolidation processes and ground water flow are described by such theories. Rapid shearing flow of granular materials lead to constitutive relations for the stresses which incorporate rate independent behavior of Mohr-Coulomb type together with dispersive stress contributions due to particle collisions. Rockfalls, sturzstroms, snow and ice avalanches, but also debris flow and sea ice drifting can be described with such formulations.

The topics covered include soil mechanics and porous media, glacier and ice dynamics, climatology and lake physics, climate change as well as numerical algorithms. The book, written by well-known experts, addresses researchers and students interested in physical aspects of our environment.

This is an elementary book on stress and strain theory for geologists. It is written in the belief that a sound introduction to the mechanics of continu ous bodies is essential for students of structural geology and tectonics, just as a sound introduction to physical chemistry is necessary for students of petrology. This view is shared by most specialists in structural geology, but it is not yet reflected in typical geology curricula. Undergraduates are still traditionally given just a few lectures on mechanical fundamentals, and there is rarely any systematic lecturing on this subject at the graduate level. The result is that many students interested in structure and tectonics finish their formal train ing without being able to understand or contribute to modem literature on rocks as mechanical systems. The long-term remedy for this is to introduce courses in continuum mechanics and material behavior as routine parts of the undergraduate curriculum. These subjects are difficult, but no more so than optical mineralogy or thermo dynamics or other rigorous subjects customarily studied by undergraduates. The short-term remedy is to provide books suitable for independ ent study by those students and working geologists alike who wish to improve their understanding of mechanical topics relevant to geology. This book is intended to meet the short-term need with respect to stress and strain, two elementary yet challenging concepts of continuum mechanics.

This remarkable collaboration between a mathematical physicist and a philosopher of science is concerned with foundational and conceptual issues in seismology. Their aim is to present mathematical, physical, and philosophical topics in a clear way and to clarify them when this is possible. They provide an extensive philosophical discussion of the methods of science and show how seismology fits in. They explain with care and precision the basic structure of seismology, which is built on classical continuum mechanics. Not only do they explain how various models work in seismology, but they include an extensive discussion of the nature of models and idealizations.

The book integrates theory, numerical methods, and practical applications seamlessly. MATLAB and MathCad programs are provided for readers to master the theory, understand the approach, and to further develop and apply the methods to geological problems. Multiscale and multi-physics investigations of Earth and planetary processes have been an active trend of research in Earth Sciences, thanks to the development of scientific computation and computer software and hardware. Based on the author's research and teaching over the past 15 years, the book stands alone as the first comprehensive text in unifying fundamental continuum micromechanics theory, geometric/kinematic analysis, and applications. The book should appeal to a broad audience of students and researchers, particularly those in the fields of structural geology, tectonics, (natural and experimental) rock deformation, mineral physics and rheology, and numerical modeling of multiscale and coupling processes.

TECTONlCS AND PHYSICS Geology, although rooted in the laws of physics, rarely has been taught in a manner designed to stress the relations between the laws and theorems of physics and the postulates of geology. The same is true of geophysics, whose specialties (seismology, gravimetIy, magnetics, magnetotellurics) deal only with the laws that govern them, and not with those that govern geology's postulates. The branch of geology and geophysics called tectonophysics is not a formalized discipline or subdiscipline, and, therefore, has no formal laws or theorems of its own. Although many recent books claim to be textbooks in tectonophysics, they are not; they are books designed to explain one hypothesis, just as the present book is designed to explain one hypothesis. The textbook that comes closest to being a textbook of tectonophysics is Peter 1. Wyllie's (1971) book, The Dynamic Earth. Teachers, students, and practitioners of geology since the very beginning of earth science teaching have avoided the development of a rigorous (but not rigid) scientific approach to tectonics, largely because we earth scientists have not fully understood the origin of the features with which we are dealing. This fact is not at all surprising when one considers that the database for hypotheses and theories of tectonics, particularly before 1960, has been limited to a small part of the exposed land area on the Earth's surface.